In semiconductor manufacture, different types of components have been developed recently, that are smaller and have a higher input/output capability than conventional plastic or ceramic packages. For example, one type of semiconductor component is referred to as a chip scale package (CSP) because it has an outline, or “footprint”, that is about the same as the outline of the die contained in the package.
Typically, a chip scale package includes a dense area array of solder bumps, such as a standardized grid array as disclosed in U.S. Pat. No. 6,169,329 to Farnworth et al. The solder bumps permit the package to be flip chip mounted to a substrate, such as a package substrate, a module substrate or a circuit board. Another type of component, referred to as a bumped die, can also include solder bumps in a dense area array. Bumped dice are sometimes considered as the simplest form of a chip scale package. Another type of component, referred to as a BGA device, is also sometimes considered a chip scale package. Yet another type of component as disclosed in U.S. Pat. No. 6,150,717 to Wood et al. is referred to as a direct die contact (DDC) package,
The quality, reliability and cost of these types of components is often dependent on the fabrication method. Preferably a fabrication method is performed on a substrate, such as a semiconductor wafer, containing multiple components, in a manner similar to the wafer level fabrication of semiconductor dice. A wafer level fabrication method permits volume manufacture with low costs, such that the components are commercially viable.
In addition to providing volume manufacture, the fabrication method preferably produces components that are as free of defects as possible. In this regard, semiconductor dice include relatively fragile semiconductor substrates that are susceptible to cracking and chipping. It is preferable for a fabrication method to protect the dice, and prevent damage to the fragile semiconductor substrates of the dice. Similarly, it is preferable for the completed components to have structures which provide as much protection as possible for the dice.
The present invention is directed to a novel wafer level fabrication method for fabricating semiconductor components, such as chip scale packages, BGA devices and DDC devices, in large volumes, at low costs, and with minimal defects. In addition, the fabrication method produces components with increased reliability, and with a chip scale outline, but with the dice protected on six surfaces by polymer layers.